Energy storage type heat supply system based on middle-deep layer interference-free geothermal energy

Abstract

The utility model discloses an energy storage type heat supply system based on middle-deep layer interference-free geothermal energy, which comprises a water replenishing unit, a middle-deep layer geothermal well, a heat pump unit, a water segregator, a water collector and an energy storage unit, and the energy storage unit comprises an energy storage water tank and a heat exchanger; a heat supply pipeline of the heat pump unit is provided with a heat supply main pipe, a first branch and a second branch, the first branch is communicated with the water segregator, the second branch is communicated with the energy storage water tank, and a heat storage water return pipe of the energy storage water tank is communicated with a heat supply water return main pipe of the heat pump unit; the energy storage water tank is further provided with a heat release pipeline, and the heat release pipeline flows back to the energy storage water tank. Water supply of the heat pump unit is divided into two paths, one path is directly connected with the water segregator, and user return water flows back to the heat pump unit through the water collector and can be used for peak electricity heat supply; heat storage can be achieved, heat supply and heat storage can be achieved at the same time in the valley electricity period, heat supply can be conducted through stored heat in the peak electricity period, the system is ingenious, and the operation energy consumption of the whole system is reduced.

Description

Technical Field

[0001] The utility model relates to the field of heating, in particular to an energy storage type heating system based on mid-deep layer non-interference geothermal energy. Background Art

[0002] As a non-carbon-based clean energy, geothermal energy has a lot of advantages such as continuity, stability, and exploitable resources. It has broad application prospects in the field of heating. However, shallow soil source heat pumps have problems such as large heat exchange plane area, difficult heat sink balance, and reduced energy efficiency after long-term use. Medium-deep non-interference geothermal energy technology, also known as dry hot rock geothermal technology, also known as medium-deep buried pipe technology, drills geothermal wells into high-temperature hot rock at a depth of 2~3km underground, installs a closed coaxial sleeve heat exchanger in the well, and uses the closed circulation formed by the heat exchange medium in the well to extract heat from geothermal energy without taking water. For example, the heat energy provided by a borehole with a depth of 2500m and an aperture of 200mm is equivalent to the heat taken by 100 shallow buried pipes, which can solve the heating problem of about 15,000 square meters of residential buildings.

[0003] Existing projects have proven that deep-layer non-interference geothermal energy is also stable and reliable as a long-term heat source. Existing project operation data show that 80% of the annual operating cost of the system is the electricity cost of heat pumps and various water pumps, and the remaining 20% ​​is labor costs, equipment maintenance, etc. Compared with traditional carbon-based fossil energy, energy consumption and operating costs are greatly reduced. At present, the research on deep-layer non-interference geothermal heating technology is mostly focused on the research and development of coaxial shell and tube heat exchangers, high-temperature heat pumps and other equipment, the improvement of underground well construction technology, the stability of the system, the continuous heat extraction capacity, the intelligent informationization of the system, etc., and does not involve related research on heat storage. Summary of the invention

[0004] In view of this, the utility model proposes a storage-type heating system based on mid-deep interference-free geothermal energy, which can realize heating and heat storage during valley power periods, and use the stored heat for heating during peak power periods, thereby reducing the operating energy consumption of the entire system and thus reducing the operating cost of the entire system.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] The energy storage heating system based on mid-deep non-interference geothermal energy described in the utility model comprises a water replenishment unit, a mid-deep geothermal well, a heat pump unit, a water distributor and a water collector; it also comprises an energy storage unit, the energy storage unit comprises an energy storage water tank and a heat exchanger connected to the heat pump unit; the heating pipeline of the heat pump unit comprises a heating main pipe, a first branch and a second branch, the first branch is connected to the water distributor, the second branch is connected to the energy storage water tank, the heat storage return pipe of the energy storage water tank is connected to the heating return pipe of the heat pump unit, the heating main pipe is provided with a fifth valve, and the heating return pipe is provided with a sixth valve; the first branch is provided with a seventh valve, the second branch is provided with an eighth valve, and the heat storage return pipe is provided with an eleventh valve;

[0007] The energy storage water tank also has a heat release pipeline, which flows back to the energy storage water tank after passing through the first channel of the heat exchanger, and a thirteenth valve is provided on the heat release return pipe of the heat release pipeline, and a ninth valve is provided on the heat release water supply pipe of the heat release pipeline; the water collector is connected to a second circulation pump through a pipeline, and the outlet end of the second circulation pump is divided into two paths, wherein the first path enters the water distributor through the second channel of the heat exchanger, and the fourteenth valve and the tenth valve are respectively provided on the first path located on both sides of the heat exchanger; the second path is connected to the heating return water main, and the twelfth valve is provided on the second path;

[0008] Among them, a geothermal water supply pipeline and a geothermal return pipeline are connected between the medium-deep geothermal well and the heat pump unit. The geothermal water supply pipeline near the heat pump unit is provided with a first circulation pump and a third valve, and the geothermal return pipeline near the heat pump unit is provided with a fourth valve.

[0009] The beneficial effect is: the utility model divides the water supply of the heat pump unit into two routes, one route is directly connected to the water distributor, and the user's return water flows back to the heat pump unit through the water collector, which can be used for peak power heating; the other route is connected to the energy storage water tank to realize heat storage. During the off-peak power period, it can provide heat and store heat at the same time, and during the peak power period, the stored heat can be used for heating. The system is ingenious, which reduces the operating energy consumption of the entire system, thereby reducing the operating cost.

[0010] Preferably, temperature sensors are installed in the water distributor, water collector and energy storage water tank, and pressure sensors are installed in the water distributor and water collector. The signal output end of each temperature sensor and the signal output end of each pressure sensor are electrically connected to the signal input end of the controller, so that the heat storage and heat release of the energy storage water tank water can be flexibly adjusted according to the temperature.

[0011] Preferably, the water replenishment unit includes a soft water pipeline connected to tap water, and a first valve, a flow meter, a softening water device, a water tank and a water replenishment pump are sequentially arranged on the soft water pipeline; there are two water replenishment units, one of which is connected to the geothermal return water pipeline to provide circulating water to the system; the other water replenishment unit is connected to the water collector to replenish water to ensure the dynamic balance of the water distributor and the water collector.

[0012] Preferably, the first circulating pump and the second circulating pump are both in two groups; the heat exchanger is a plate heat exchanger; and the heat pump unit is a variable frequency centrifugal heat pump unit. In actual installation, there are two circulating pumps, one for backup and one for use, which effectively ensures the normal operation of the entire system and can also achieve alternating maintenance.

[0013] Preferably, the energy storage heating system described in the utility model further includes a peak-shaving heat source, the hot water supply pipeline of the peak-shaving heat source is connected to the water distributor, and a fifteenth valve is provided on the hot water supply pipeline; the hot water return pipeline of the peak-shaving heat source is connected to the water collector, and a sixteenth valve is provided on the hot water return pipeline. After the deep geothermal stops taking heat, the heat source water in the buried pipe can still absorb heat from the surrounding soil, so that the outlet water temperature is significantly increased when the next stage is started, thereby increasing the heat taken in a short time.

[0014] The beneficial effect is that the utility model combines the peak-shaving heat source with the mid-deep non-interference geothermal energy, thereby fully improving the geothermal heat extraction and further reducing the operating cost of the entire system.

[0015] Preferably, the water distributor and the water collector are connected via a differential pressure balancing pipeline, and a differential pressure bypass valve is provided on the differential pressure balancing pipeline. The differential pressure balancing pipeline and the differential pressure bypass valve in the utility model effectively ensure the pressure stability of the return water of the entire system and ensure the dynamic stability of the return water pressure.

[0016] Compared with the prior art, the advantage of the utility model is that the water supply of the heat pump unit is divided into two routes, one route is directly connected to the water distributor, and the user's return water flows back to the heat pump unit through the water collector, which can be used for peak power heating; the other route is connected to the energy storage water tank, which can realize heating and heat storage during off-peak power periods, and the stored heat can be used for heating during peak power periods. The system is ingenious, which reduces the operating energy consumption of the entire system, thereby reducing operating costs.

[0017] In addition, since the heat from the energy storage tank is mainly used for heating during peak power periods, the geothermal energy works intermittently. The instantaneous heat extraction after restart is significantly higher than that before shutdown, thereby increasing the unit heat extraction of the geothermal energy and minimizing the operating energy consumption of the entire system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the utility model. DETAILED DESCRIPTION

[0019] The following is a detailed description of an embodiment of the utility model in conjunction with the accompanying drawings. This embodiment is implemented on the premise of the technical solution of the utility model, and a detailed implementation method and a specific operation process are given, but the protection scope of the utility model is not limited to the following embodiment.

[0020] It should be noted that, in the description of the present utility model, relational terms such as "first" and "second" are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0021] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected" and "connection" that may appear should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0022] like Figure 1 As shown, the energy storage heating system based on medium-deep non-interference geothermal energy described in the utility model includes a water replenishment unit, a medium-deep geothermal well 1 (with buried pipes), a heat pump unit 2, a water distributor 3, a water collector 4 and an energy storage unit; a geothermal water supply pipeline L1 and a geothermal return water pipeline L2 are connected between the heat pump unit 2 (preferably a low-temperature centrifugal heat pump unit 2, with a maximum temperature of ≤75°C) and the medium-deep geothermal well 1 (with buried pipes), and a first circulating pump P1 is provided on the geothermal water supply pipeline L1 to provide power for geothermal water and pump the geothermal water to the heat pump unit 2; a third valve F3 is provided on the geothermal water supply pipeline L1 close to the heat pump unit 2, and a fourth valve F4 is provided on the geothermal return water pipeline L2 close to the heat pump unit 2;

[0023] The energy storage unit includes an energy storage water tank 5 and a heat exchanger 6 connected to the heat pump unit; the heat supply pipeline of the heat pump unit 2 includes a heat supply main pipe, a first branch L3 and a second branch L4, the first branch L3 is connected to the water distributor 3, the second branch L4 is connected to the energy storage water tank 5, the heat storage return pipe L5 of the energy storage water tank 5 is connected to the heat supply return pipe L6 of the heat pump unit 2, the heat supply main pipe is provided with a fifth valve F5, and the heat supply return pipe L6 is provided with a sixth valve F6; the first branch L3 is provided with a seventh valve F7, the second branch L4 is provided with an eighth valve F8, and the heat storage return pipe L5 is provided with an eleventh valve F11;

[0024] The energy storage water tank 5 is also connected to a heat release pipeline L7, which flows back to the energy storage water tank 5 after passing through the first channel of the heat exchanger 6, and a thirteenth valve F13 is provided on the heat release return water pipe of the heat release pipeline L7, and a ninth valve F9 is provided on the heat release water supply pipe of the heat release pipeline L7; the user return water pipeline is connected to the water collector 4, and the water collector 4 is connected to the second circulation pump P2 through a pipeline, and the outlet end of the second circulation pump P2 is divided into two paths, wherein the first path L8 enters the water distributor 3 through the second channel of the heat exchanger 6, and the fourteenth valve F14 and the tenth valve F10 are respectively provided on the first path on both sides of the heat exchanger 6; the second path L9 of the second circulation pump P2 is connected to the heating return water main L6, and the second path L9 is provided with a twelfth valve F12, so that the return water flows back to the heat pump unit 2, and then enters the medium-deep geothermal well 1 through the geothermal return water pipeline L2 to absorb heat;

[0025] There are two water replenishment units, which are respectively recorded as the first water replenishment unit and the second water replenishment unit. The first water replenishment unit includes a soft water pipeline L10 connected to tap water. The first valve F1, flow meter 7, softening water device 8, soft water tank 9 and first water replenishment pump P3 are sequentially arranged on the soft water pipeline L10. The outlet of the first water replenishment pump P3 is connected to the geothermal return water pipeline L2. During the system trial operation stage, the first water replenishment unit is used to supply water to the geothermal return water pipeline L2 so that the amount of water entering the medium-deep well reaches the set value to ensure the circulating water volume of the entire system and further determine the geothermal outlet water temperature; during normal operation, the first water replenishment pump P3 and the first valve F1 are in a normally closed state.

[0026] Combination Figure 1 It can be seen that the water distributor 3 and the water collector 4 are connected via a pressure differential balancing pipeline L13, and a pressure differential bypass valve F17 is provided on the pressure differential balancing pipeline L13, which effectively ensures the pressure stability of the return water of the entire system and ensures the dynamic stability of the return water pressure.

[0027] The second water replenishment unit is the same as the first water replenishment unit. For the convenience of distinction, the valve and the water replenishment pump of the second water replenishment unit are respectively recorded as the second valve F2 and the second water replenishment pump P4, and the outlet of the second water replenishment pump P4 is connected to the water collector 4. The second water replenishment unit serves as an emergency water replenishment pump. During the operation of the system, the second valve F2 and the second water replenishment pump P4 are in an open state to replenish water into the water collector 4. The water distributor 3 and the water collector 4 are connected through a pressure differential balance pipeline. When the pressure in the water distributor 3 reaches the maximum limit, the second valve F2 and the second water replenishment pump P4 are closed to stop replenishing water.

[0028] In actual projects, the utility model also includes a peak-shaving heat source, that is, using the peak-shaving heat source and geothermal heat to jointly ensure the heating during the entire heating period, such as 80% geothermal heat + 20% peak-shaving heat source, the two working alternately, which can increase the heat extraction of geothermal heat to a certain extent. Among them, the peak-shaving heat source can be municipal heating, gas boiler heating, air source heat pump unit 2, solar energy + electric auxiliary heating and other heating systems. Specifically: combined with Figure 1 It can be seen that the hot water supply pipeline L11 of the peak-shaving heat source is connected to the water distributor 3, and the hot water supply pipeline L11 is provided with a fifteenth valve F15; the hot water return pipeline L12 of the peak-shaving heat source is connected to the water collector 4, and the hot water return pipeline L12 is provided with a sixteenth valve F16. If the water distributor 3, the water collector 4 and the outdoor air temperature all reach the corresponding minimum values, the fifteenth valve F15 and the sixteenth valve F16 can be opened, and the peak-shaving heat source can be used to supply heat until the water distributor 3, the water collector 4 and the outdoor air temperature all reach the corresponding maximum values.

[0029] During actual installation, temperature sensors are installed in the water distributor 3, water collector 4, and energy storage water tank 5 to monitor the temperature in the water distributor 3, water collector 4, and energy output water tank, respectively. Pressure sensors are installed in the water distributor 3 and water collector 4 to monitor the pressure. The signal output ends of the temperature sensor and the pressure sensor are connected to the signal input end of the controller, the control input end of each valve is connected to the control output end of the controller, and the control input end of each circulation pump and each water supply pump is also connected to the control output end of the controller, so as to use the controller to control heating, peak heating, heat storage, and heat release.

[0030] The trial operation process of the utility model is as follows: during the trial operation, open the first valve F1 and the first water supply pump P3 to supply water to the buried pipe in the deep well until the water volume in the buried water reaches the set value; open the first circulation pump P1, the third valve F3, the fifth valve F5, the sixth valve F6, the seventh valve F7, the second circulation pump P2, the twelfth valve F12 and the fourth valve F4, so that the geothermal water first enters the heat pump unit 2, enters the water distributor 3 after heat exchange, and is sent to the user's water supply pipeline by the water distributor 3; the user's return water pipeline is connected to the water collector 4, and the second circulation pump P2 pumps the return water into the heat pump unit 2, and then enters the buried pipe through the geothermal return water pipeline L2, and the cycle is repeated until the system is stable. During the trial operation, the circulating water volume can be flexibly adjusted according to actual needs by controlling the opening and disconnection of the first valve F1 and the first water supply pump P3. During the trial operation, the second valve F2 and the second water supply pump P4 can be opened at the same time to supply water to the water collector 4 until the pressure in the water distributor 3 reaches the maximum limit and then the second valve F2 and the second water supply pump P4 are closed.

[0031] During the normal operation of the system, the third valve F3, the fourth valve F4, the fifth valve F5, the sixth valve F6, the seventh valve F7 and the twelfth valve F12 are all normally open valves, and the first circulation pump P1 and the second circulation pump P2 are in the open state. Normal operation is divided into valley power period and peak power period. During the valley power period, heat can be supplied and stored at the same time. The specific process is as follows: geothermal water is pumped into the heat pump unit 2 through the first circulation pump P1, and is divided into two paths after heat exchange. One path enters the water distributor 3, and then enters the user's water supply pipeline. The return water enters the water collector 4 through the user's return water pipeline, and flows back to the heat pump unit 2 under the action of the second circulation pump P2, and then enters the buried pipe through the geothermal return water pipeline L2. In this way, the cycle is circulated to achieve heating; the other path enters the energy storage tank 5, and the bottom of the energy storage tank 5 is connected to the heat pump unit 2, that is, hot water is injected into the energy storage tank 5, and the low-temperature water in the energy storage tank 5 is taken away until the temperature rises to 55°C;

[0032] When the water temperature of the energy storage water tank 5 reaches 55°C, the seventh valve F7 and the twelfth valve F12 are closed, and the eighth valve F8, the ninth valve F9, the tenth valve F10, the eleventh valve F11, the thirteenth valve F13 and the fourteenth valve F14 are opened. At this time, the hot water from the heat pump unit 2 enters the energy storage water tank 5 through the second branch L4, and the return water flows back to the heat pump unit 2 through the heat storage return pipe L5, and then enters the buried pipe through the geothermal return pipe L2 to continue to store heat in the energy storage water tank 5; the energy storage water tank 5 enters the heat exchanger 6 under the action of the fifth pump P5, and performs heat exchange with the return water flowing through the heat exchanger 6, that is, the hot water in the energy storage water tank 5 performs heat exchange with the return water from the water collector 4, and the return water becomes hot water after heat exchange and directly enters the water distributor 3 to realize heating;

[0033] When the water temperature in the energy storage water tank 5 reaches 75°C, the eighth valve F8, the ninth valve F9, the tenth valve F10, the eleventh valve F11, the thirteenth valve F13 and the fourteenth valve F14 can be closed, and the seventh valve F7H and the twelfth valve F12 can be opened, and the hot water from the heat pump unit 2 directly enters the water distributor 3 through the first branch L3, and the return water from the water collector 4 also directly flows back to the heat pump unit 2, that is, the geothermal + heat pump unit 2 continues to supply heat until the peak power period is reached.

[0034] During the peak power period, the third valve F3, the fourth valve F4, the fifth valve F5, the sixth valve F6, the seventh valve F7, the eighth valve F8, the eleventh valve F11 and the twelfth valve F12 are closed, and the first circulation pump P1 is closed; the ninth valve F9, the tenth valve F10, the thirteenth valve F13, the fourteenth valve F14 and the fifteenth valve F15 are opened, and the hot water in the energy storage water tank 5 enters the heat exchanger 6 through the heat release water supply pipe, and enters the energy storage water tank 5 through the heat release water return pipe after heat exchange; the return water of the water collector 4 is pumped into the heat exchanger 6 under the action of the second circulation pump P2, so that it exchanges heat with the hot water from the energy storage water tank 5, and directly enters the water distributor 3 after heat exchange to realize the heating of the energy storage water tank 5; when the temperature of any one of the water distributor 3 and the water collector 4 is lower than 35°C, the heating of the energy storage water tank 5 is closed, and the geothermal + heat pump unit 2 is used again for heating to meet the user's heating demand.

[0035] It should be pointed out that the controller in the present invention can be a general processor, a special processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) circuit, any other type of integrated circuit (IC) and a state machine, etc. It can also be a PLC controller, or an industrial computer with important computer properties and characteristics, etc. Further, the controller can also be provided with a wireless communication module to achieve connection with a remote terminal, receive control instructions from the remote terminal, and also feedback relevant parameters of the real-time working status.

[0036] Finally, it should be emphasized that the above is only a preferred embodiment of the utility model and is not intended to limit the utility model. Although the utility model is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions recorded in the aforementioned embodiments without creative work, or replace some of the technical features therein with equivalents. Therefore, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. An energy storage heating system based on mid-deep non-interference geothermal energy, comprising a water replenishment unit, a mid-deep geothermal well, a heat pump unit, a water distributor and a water collector; characterized in that: It also includes an energy storage unit, which includes an energy storage water tank and a heat exchanger connected to the heat pump unit; the heat supply pipeline of the heat pump unit includes a heat supply main pipe, a first branch and a second branch, the first branch is connected to the water distributor, the second branch is connected to the energy storage water tank, the heat storage return pipe of the energy storage water tank is connected to the heat supply return pipe of the heat pump unit, the heat supply main pipe is provided with a fifth valve, and the heat supply return pipe is provided with a sixth valve; the first branch is provided with a seventh valve, the second branch is provided with an eighth valve, and the heat storage return pipe is provided with an eleventh valve; The energy storage water tank also has a heat release pipeline, which flows back to the energy storage water tank after passing through the first channel of the heat exchanger, and a thirteenth valve is provided on the heat release return pipe of the heat release pipeline, and a ninth valve is provided on the heat release water supply pipe of the heat release pipeline; the water collector is connected to a second circulation pump through a pipeline, and the outlet end of the second circulation pump is divided into two paths, wherein the first path enters the water distributor through the second channel of the heat exchanger, and the fourteenth valve and the tenth valve are respectively provided on the first path located on both sides of the heat exchanger; the second path is connected to the heating return water main, and the twelfth valve is provided on the second path; A geothermal water supply pipeline and a geothermal return pipeline are connected between the medium-deep geothermal well and the heat pump unit. A first circulation pump and a third valve are arranged on the geothermal water supply pipeline near the heat pump unit, and a fourth valve is arranged on the geothermal return pipeline near the heat pump unit.

2. The energy storage heating system based on mid-deep non-interference geothermal energy according to claim 1 is characterized in that: The water distributor, water collector and energy storage water tank are all equipped with temperature sensors, and the water distributor and water collector are all equipped with pressure sensors. The signal output end of each temperature sensor and the signal output end of each pressure sensor are electrically connected to the signal input end of the controller.

3. The energy storage heating system based on mid-deep non-interference geothermal energy according to claim 1 is characterized in that: The water replenishment unit includes a soft water pipeline connected to tap water, on which a first valve, a flow meter, a softening water device, a water tank and a water replenishment pump are sequentially arranged; there are two water replenishment units, one of which is connected to the geothermal return water pipeline, and the other is connected to the water collector.

4. The energy storage heating system based on mid-deep non-interference geothermal energy according to claim 1 is characterized in that: The first circulation pump and the second circulation pump are both in two groups; the heat exchanger is a plate heat exchanger; and the heat pump unit is a variable frequency centrifugal heat pump unit.

5. The energy storage heating system based on mid-deep non-interference geothermal energy according to claim 1 is characterized in that: It also includes a peak-shaving heat source, the hot water supply pipeline of the peak-shaving heat source is connected to the water distributor, and a fifteenth valve is arranged on the hot water supply pipeline; the hot water return pipeline of the peak-shaving heat source is connected to the water collector, and a sixteenth valve is arranged on the hot water return pipeline.

6. The energy storage heating system based on mid-deep non-interference geothermal energy according to claim 1 is characterized in that: The water distributor and the water collector are connected via a pressure differential balancing pipeline, and a pressure differential bypass valve is arranged on the pressure differential balancing pipeline.

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